December 23, 2014

Silverlit X-Twin Remote with External Power Supply

I recently stumbled across a lot of small scale RC planes using LiPo batteries and most of them had a charger integrated into the battery powered remote. Why waste batteries on charging when you can use an external power supply?

Click here to see the detailed tutorial on how to mod your Silverlit X-Twin remote to support external and internal power at the flick of a switch!

This is what the remote should look like after you're done.

There is a switch at the top left of the remote, it determines if the remote runs on batteries or external power. You can see the plug from the external power supply at the bottom left.There's also a video about the whole mod available:

Now let's get started! You will need the following parts:

A 9V DC power supply, a 2 kOhm resistor, a 6 pin toggle switch and male/female connector combo.Let's take a look inside the remote. Unscrew the antenna, take out all batteries and remove all screws on the back side.

Here we can see the pcb with its connections coming from the battery compartment.

We have +9V at the top, +4.5V at the middle and ground at the bottom. This remote needs two different voltages, +9V for the charging circuit on the left and +4.5V for the emitter logic on the right. Not all remotes have got this specific layout and if your remote seems not to have another connection to the batteries besides one with all batteries in series (maybe 6V, 9V or 12V), ignore all further steps involving the resistor, white cable and middle +4.5V contact and use a 3 pin toggle switch instead of a 2*3 pin one.

Now desolder the +9V cable at the top and lengthen it by some centimeters with a red cable. Do the same accordingly for the white cable in the middle.Solder red and white to the switch's middle contacts as seen here. (Ignore the white cable if your remote only has one main connection to the batteries, as mentioned above)

Take two pieces of cable, red and white. Now solder the red one to the main +9V connection and the white one to the main +4.5V contact.

Next solder the red one to one pin on the red side of the switch, do the same for the white one. It should look like this:

Now we're almost finished! Solder the female connector socket's red cable to the last pin on the red side of the switch, then solder the black cable to ground at the bottom of the battery case.

Here a quick overview.

If your remote does only have one main battery connection you can stop here. In order to provide the +4.5V for the middle contact when in external power mode I soldered a 2kOhm resistor into place.Just connect one end of the resistor to the remaining pin on the switche's white side and the other to the red cable coming from the female connector socket.

The switch now determines what power source the remote pcb's contacts get connected to - either batteries or the external plug.Cut notches into the remote's hull, fit inside the switch and connector and glue them in place with the help of some hotglue.

The last step is attaching a male connector piece to your DC +9V power supply.

If you have any problems with this tutorial, try the video! This tutorial should help you with this specific remote but also give you an idea for other remotes with maybe higher or lower voltages. If you leave out the instructions about the white cable, resistor and use only a 3 pin toggle switch, you should be able to mod almost any remote control yourself - given you find the right DC power supply - .